Intereror lights blink at night-1997

Last night before I went to bed, I happened to look out the window to see my interior lights blinking. I thought someone was trying to get into my car. When I went out, the car was OK, nobody there. The interior lights where blinking. I made sure all the doors where shut, adjusted the dimmer switch, nothing stopped it.
When I woke up this morning the lights where still blinking. Seemed more on then off in the morning.
What in the world would cause this? Any ideas? Thank you, Chris.

There may be some sort of relay causing the problem. Until you figure it out, though, I reccommend pulling the fuse on them so they don't run the battery down.

If I pull the fuse, will I get a check engin light? I would of thought if a relay was going out I would of got a light already.

No service engine soon light, just no interior lights will come on.

The Service Engine light primarily lights for engine/powertrain malfunctions related to the emissions control systems. That's pretty well the reason it exists. The computer monitors other things, but it usually doesn't turn the light on for them.

I know of no relay for controlling the interior lights on my 1995. Fuel pump, door locks, trunk release... no lights. My guess would be one of the door latch sensors is going to pot. Can't deicede if the door is latched or not...

Though, that should produce a random flashing. Is the flashing random or is there a regular pattern?

Problem is random. I stoped in at the dealer. He said a relay has nothing to do with it. I have goten bad answers from them in the past, so not sure what to think when they tell me somtheing.

Another person walked by as I was talking to the guy and he said, "Sounds like a problem with the security system." The guy asked if it has a alarm. I told him no. He asked if it has a remote doorlock. I said yes. He said it could be a problem with that part. I think he thought it was a consistant pattern, because he added, some cars when you lock the doors with the remote, it blinks the lights.

The person at the service Dept. said he has been working at the dealer for 15 years and has never herard of this before at all. "Have no way of knowing at all. We would have to just get in there and start looking around and testing eveything."

That sounds expensive. Any way I could test to find out what is wrong? Wonder if the "sencer' could be dirty?
What should I look for? Thanks for the reply, Chris.

P.S. After I typed this, I remembered about a day or two before this, I went out to my car and the trunk was poped. I thought maybe I hit the two buttons on accedent. Maybe it does have something to do with the Keyless Remote? When I open the doors with the remote, the lights go on. When I lock it, the lights go out, so the keyless does have something to do with the intior lights. How do I check the Door Sensor and the Keyless remote?

Yeah. Standard dealer response. "Don't know, you'll just have to bring it in, so we can charge you $75/hour to take it apart, $75/hour to read the wrong parts of the book trying to find the problem, $75/hour to take the other side of the car apart, and $75/hour to put the car back together after accomplishing nothing."

The door latch sensor is built into the door latching mechanism. You have to remove the door panel, disconnect the rods from the handles and lock actuators, and then remove the latch from the inside of the door.

Testing would be difficult, as it's intermintant, but you could unplug the connector from the latch and check the contacts to make sure they are clean and the wires aren't loose. Still have to remove the door panel.

On my 95 LeSabre, the keyless entry reciever is mounted to a white plastic bracket, behind the glove box, in front of the secondary relay/fuse panel. However, they more things on every model, every year. For example, on the 95 Century, it is mounted in the trunk near the drivers side rear speaker.

Easiest way to test would be to borrow one out of another 2000 LeSabre/ParkAve/Bonneville/Olds98 (I think the Olds 98 is the same body) and swap them. If the problem moves with the box, replace the box.

However, side note. You'll notice a number on your key fob and on the keyless reciever that are very similar. The FCC ID / Frequency. They likely both begin with ABO, the next 4 numbers will be the same, then a T or an R. (T=Transmitter=Key Fob, R=Reciever=Keyless Entry Module.)

I was looking for a new reciver on the internet. I can't find one at all. Do you know anyware to buy a Remote Reciver on the net?

I would just see if a friend has a car that you could borrow it out of, or if you could get one from a junkyard. I don't really trust giving credit card info to people online, but that is just my own paranioa.

My interior lights are on a relay in my car, so I figured those would be as well. But ten years does make a difference. With a keyless remote, there is a possibility that there is some sort of relay for the lights, to control the flashes, but I am not at all familiar with the remote system. So...back to someone who knows better than I about remote systems.

Interior lights do not normally flash in any car that I know of. Not even for a security feature or alarm that I have ever seen. The parking lights flash, the horn flashes, but not the interior lights. If anyone knows of a car that does, it's definately non-standard compared to everything else on the market.

As newer cars have keyless entry, they also have lighting control modules. Relays have been replaced with micro-relays and IC chips mounted to a circuit board.

Sounds like for me to change up to four door latch sensers, Keyless Reciver, etc.. trying to track down what can be wrong could be way more then having the dealer $75/hour to take it apart, $75/hour to read the wrong parts of the book trying to find the problem, $75/hour to take the other side of the car apart, and $75/hour to put the car back together. If this is the case, with no way to find out what it is, I guess I'll just have to have the lights flashing 24 hours a day.
One thing I don't like is it brings attention to my car at night. If anybody has any more ideas, keep the suggestions coming. Thank you, Chris.

First step - Pull the coutesy lamps fuse, then you won't have to worry about the lights flashing at night and running your battery dead.

Then begins the process of slowly troubleshooting the possible causes.

As the lights are clicking on and off... it could definately be a bad relay. BuickMasterMind is right, there could be a relay... I pretty well know ever relay in my car and I don't know of one... but there might be one.

There shouldn't be any relays in the fuse box, but I know there are two in my 1995 that are above the drivers lower panel (the thing the fuse box is mounted to). One is for the blinkers and I haven't cared to know what the other is for. The blinker one is hooked to a fitting on the panel near the fuse box, and I believe the other one is some other stupid place.

Then there are a couple relays behind the glove box, the fuel pump, trunk latch release, drivers door unlock, I think the ride control is in there as well. Remove the glove box, and you'll be able to see the relays mounted to a fuse box on the passenger wall, in the most inaccessable place imaginable. (I have to slide out my keyless reciever to get enough room to touch mine.)

Then there are about a dozen relays under the hood in the Maxi Fuse and Relay Panel. These control things like the A/c compressor, blower fans, etc, etc, etc. The neat little relays have special retaining clips that hold them in. So special that I have never found it necessary to find an easy way to release them.

Alright, now, the important part, testing the relays. I would recommend starting by NOT removing any of them. Instead I would just listen, close all the doors, turn off the radio, and listen. See if you can hear a relay clicking on and off with the lights. Then follow the sound. When you get close, you should be able to put your finger on the relay making the noise and feel it clicking back and forth.

(Though you will likely have to remove the glove box, drivers lower panel, Maxi Fuse / Relay cover, to be able to hear the relay click. It will sound a little like your blinker. However, blinker relays a DESIGNED to make noise, they purposely make more noise. Other relays are often barely audible. You'll only be able to notice it because it should be clicking on and off, over and over.)

Next thing that it could be... as the lights are clicking on and off it could be a Circuit Breaker. Modern cars now utilize several "Self Resetting Circuit Brakers" for critical systems. Instead of blowing a fuse, the circuit breaker trips, waits a few seconds, and then attempts to reset. If there is fault somewhere in wiring that involves the interior lights for some reason, the circuit breaker could be continuously over-loading and resetting. Thus, flashing your lights.

There are only three (exactly three) circuit breakers on my 1995. There are two in the drivers fuse box. They look a little like relays and have tape over them to diswade their arbitrary removal and subsequent incorrect re-installation. There is one more in the Maxi Fuse and Relay Panel in the drivers side Maxi Fuse bank. It's easy to spot as it is the same size as a Maxi Fuse but looks completely different. The fuse rating is also listed as CB-20 (Circuit Breaker 20 AMP).

Testing -- Easy. Try pulling one of them out one at a time and waiting to see if the light stop flashing. If they do, problem solved.

It would be good to reinstall them the exact same way as you took them out. Remember, they only use circuit breakers for systems that are considered critcal. (Plus, I don't expect they are cheap to replace if you blow one up.)

Now... the fun, fun, fun, fun part. You can either start with the doors, or with the light control module. The easiest and least intrusive is the light control module. I have absolutely no idea where it is, or what it looks like though. However, we'll say that you manage to find it....

Testing - Unplug it. If the lights stop flashing, then you know it has something to do with that module or the sensors and lights attached to it. If the lights do not stop flashing, it has something to do with a component not related to the module, and thus not likely the door sensors. (If the lights don't stop flashing... well... then it's gonna get complicated.)

We'll say the light stopped flashing. Find a replacement module. Borrow one of a friends car, go to the junk yard and rip one out of another car with the same part number, or go to AutoZone and buy one. (Rememeber, you can always return it the next day if it doesn't work.) Plug it in, see if the lights flash. If they don't, swap back in the bad module to confirm they still flash, then put the replacement back in. Leave it over night and see if the lights start flashing with the new module installed. If not, all is well, problem fixed.

Alright, assuming the lights still flash using a replacement --known good-- interior light control module thingy-ma-jiger. Return the part to AutoZone, install the original module, move onto the door sensors.

Now... door sensors are going to suck, as you are going to have to take apart one door after anotehr looking for the problem. I'd suggest the drivers door as that is the door that gets used most often. Then move onto the doors in order of frequency of use.

I have no clue whether the door latch indicates a closed status with a closed or open circuit. With a little testing, referencing a service manual, and then having someone here reference a service manual... We can probably figure it out.

If it's a two wire connector, you can just put and Ohm meter on the door latch connector and check it in both the latched and unlatched state. One state should read 0 Ohms the other should read 1/Infinate Ohms. You'll also likely be able to determine if the sensor is faulty, as you should be able to watch the Ohm readout and see it bounce back and forth between 0 and 1 in the latched state if the latch is bad.

Once you determine whether an open of closed circuit represents a latched state, you can then replicate this on the car. An open state, would be replicated by simply leaving the connector unplugged and seeing if the lights turn on and off. A closed state would be replicated by shorting the pins on the connector and seeing if the lights still flash on and off.

On second thought, let me simplify the above 3 paragraphs. If you have found the bad latch... when you unplug the connector from the latch, the lights should change to one state or the other. I.e. On of off. More importantly, they should stop flashing.

My guess is that a closed circuit represents a latched state. There should be a loop that runs between all the door latches, so that if any latch is opened it causes the circuit to be open, which trips a relay (either a regular relay or a micro relay on a circuit board) which turns on the lights.

Therefore, when you unplug any connector from the latch, the lights should stay on constant. You can then short the appropriate pins on the connector (known from a service manual or placing an Ohm meter on the latch as described above) and put it in a known closed state for that latch. If the lights stay off, you have found the bad latch. If they continue to flash, you have not.

You also need to pay VERY close attention to the connectors. For one, the connectors will be held in by some sort of CPA (Connect Point Assurance) device. That means the connector will not just unplug, you'll have to push, pull, or remove a pin to get the connector free. (This is prevent things like your lights flashing on and off because the connector came loose.)

Bear in mind, you won't be able to actually see the connector without completely removing the latch assembly. And removing the latch assembly involves disconnecting 3 linkages that are held in place be special connectors designed to make it a pain in the butt. Largely because you won't really be able to see the linkages or how they connect. Everything is pretty well obscured by the side of the door.

However, if you have a pinched wire anywhere in the door, a loose connector, or a loose terminal in one of the connectors, that would definately cause this problem. In fact, it is the most likely cause of this problem. Due to the fact that accessing the wires and latch assemblies involves removing the interior door panels... I felt it should be the last step. Even though it's the most likely cause, it's also the biggest pain in <blank> to troubleshoot.

Beyond that... I'm betting it's the drivers door latch causing the problem. However, troubleshooting that latch does not yield results, move onto the passenger door, and then the rear doors if need be.

I wouldn't recommend reassembling any of the doors until you have fixed the problem and it hasn't reoccured for at least a week. (Taking door panels off sucks AND the more times you remove and replace them, the greater the chances that you are going to break the exterior plastic portions. I have done it several times cussing and trying to force them back into place.)

READ THIS FIRST!!!!! Another thought that has just occured to me. Taking into account the assumptions that all the latches function in a continous loop, the a closed loop turns the lights off, an open loop turns the lights on, and that the drivers door is the most likely culprate. Do this... Open your drivers door, and observe the lights that have been flashing. Do they suddenly stop flashing? Close the drivers door, the lights should start flashing again. -- If the lights still flash with any of the doors open, then you likely have a bad latch or a bad control module. If the lights stop flashing when a door is opened, then you likely have a loose wire. -- At least that's my guess at this moment taking into account several assumptions which I cannot confirm without several dozen pages of factory wiring diagrams. LOL

Alright. I'm tired now... that's an hour worth of typing babble and my ADD meds have kicked in. Guess I should take a shower... Though I did want to be at work an hour ago. I really should stop doing this. I doubt anyone reads any of it...